The present invention relates, in general, to an artificial light source device, and in more detail, to one in which the light rays from a light source lamp are converted to parallel light rays by means of a parabola reflection mirror and the parallel light rays are guided into an optical conductor rod. Furthermore the light rays coming from the optical rod are then guided into the optical conductor cable and the light rays coming from the optical conductor cable are then employed as a light source. In such a device, the light-receiving edge of the optical conductor cable is inclined in relation to the direction of the light rays' propagation. In addition to that, a filtering film capable of letting a pre-selected part of the light pass through the light-receiving edge surface and of reflecting other pre-selected portions of the light thereon, is provided in this proposed device. In such a manner, a part of the light is separated from the rest by means of a filtering film.
In general, it is possible to illuminate any place through the use of an electric lamp. However, in the case of illuminating in an explosive atmosphere or in water, there necessarily exists a danger of explosion or electric leakage. For this reason, the electric instrument to be used in such places has to be of an explosion-proof type or a water-proof type. However, in the past, such an explosion-proof or water-proof instrument was heavy and expensive when completed, and it was also impossible to manufacture such completely explosion-proof or water-proof instruments as made possible by this new device.
Furthermore, the present applicant has previously proposed a light compound reaction device for nurturing chlorella or the like and an intensive cultivation device for cultivating plants in an atmosphere containing carbon dioxide (carbonic acid gas). In such devices, the light rays are necessary for creating a light compound reaction. In order to emit the necessary light rays for achieving its purpose, it needs to have a large number of small spotlight sources without emitting any heat and ultraviolet rays. In order to obtain the light source as mentioned above, the present applicant has previously proposed various methods and apparatuses in which solar rays are focused by a lens or the like and guided into an optical conductor cable consisting of a large number of optical fibers, and the solar rays are further guided through the optical conductor cable into the light compound reaction device of the chlorella nurturing device or the intensive plant cultivation device, and the light rays emitted from the optical fiber are employed as a spotlight source. In this regard, reference is made to U.S. Pat. No. 4,389,085 issued June 21, 1983; No. 4,420,796 issued Dec. 13, 1983; No. 4,471,412 issued Sept. 11, 1984; No. 4,523,257 issued June 11, 1985; No. 4,555,864 issued Dec. 3, 1985; and U.S. patent application Ser. No. 520,337 filed Aug. 4, 1983 U.S. Pat. No. 4,501,084.
However, if the light compound reaction device is effective even in the night time, only artificial light rays are employed instead of solar rays as the main light source. In such a case, the light rays from the artificial light source lamp are guided into the optical conductor cable and further guided through the optical conductor cable into the light compound reaction device. In such a device it is necessary to switch alternately the source of the solar rays and the source of the artificial light rays in order to employ them in an alternating way. On some occasions it is necessary to use the solar rays and the artificial light rays from both of the light ray sources at the very same time.
In an artificial light source device as described above, the light rays from an artificial light source lamp are converted to parallel light rays. The parallel light rays are guided into an optical conductor rod and are further guided through it into another optical conductor cable. When the light rays from the artificial light source lamp are guided through the optical conductor rod into the optical conductor cable in such a manner, the heat rays and the ultraviolet rays are among the light rays from the artificial light source, and the light rays or visible rays can be effectively guided into the optical conductor cable.